They are evergreenshrubs and small trees 2–20 m tall. The leaves are alternately arranged, simple, thick, serrated, usually glossy, and 3–17 cm long. The flowers are large and conspicuous, 1–12 cm diameter, with (in natural conditions) 5–9 petals; colour varies from white to pink and red, and yellow in a few species. The fruit is a dry capsule, sometimes subdivided into up to 5 compartments, each compartment containing up to 8 seeds.

The genus is generally adapted to acidicsoils, and does not grow well on chalk or other calcium-rich soils. Most species also have a high rainfall requirement and will not tolerate drought. Some Camellias have been known to grow without much rainfall.

Many other camellias are grown as ornamental plants for their flowers; about 3,000 cultivars and hybrids have been selected, many with double flowers. Camellia japonica (often simply called Camellia) is the most prominent species in cultivation, with over 2,000 named cultivars; next are C. reticulata, with over 400 named cultivars, and C. sasanqua, with over 300 named cultivars. Popular hybrids include C. × hiemalis (C. japonica × C. sasanqua) and C. × williamsii (C. japonica × C. saluenensis). They are highly valued in Japan and elsewhere for their very early flowering, often among the first flowers to appear in the late winter. Late frosts can damage the flowers.

Fiction

In Akira Kurosawa's 1962 film, Sanjuro, the main character takes on the surname 'Tsubaki' meaning camellia, which he happened to be looking at when asked for his name.

The 1942 film Now Voyager starring Bette Davis as Charlotte Vale a middle aged spinster woman who is treated psychiatrically and as part of her treatment goes away on a cruise. While there she is romanced by a very charming Paul Henreid who affectionately calls her Camille and gives her camellias.

In the manga Fruits Basket, the character Akito has a fondness for the camellia. This is because her true love, the character Shigure, gave her a camellia in their youth and proclaimed his love for her.

In the manga Soul Eater, the character Tsubaki is named for the flower, and it is constantly brought up in episodes 10 and 11, that the way the scentless flower dies is tragic and unsettling, a reference to what would've occurred in battle, if Tsubaki hadn't had the emotional support from her partner, which allowed her to succeed in the fight against her brother, as she claimed that the Camellia did in fact have a scent.

In chapter 11 of the novel To Kill A Mockingbird, Jem receives one from the old lady he took care of after her death.